The present invention relates to an X-ray computed tomography (CT) image production method and an X-ray CT system. More particularly, the present invention is concerned with an X-ray CT image production method and an X-ray CT system that reconstruct an image by utilizing a plurality of projection data items acquired with X-rays which pass through the same pixel location in the same scan field while being transmitted along different paths with a scanner gantry set at the same view angle or an opposite view angle.
Conventionally, X-ray CT systems are known (refer to, for example, Patent Document 1) to be such that: projection data is acquired while an X-ray tube and a multi-channel detector are rotated about a subject and a tabletop on which the subject lies down is rectilinearly moved; projection data items acquired with X-rays that pass through a pixel location in a scan field are sampled in order to produce a data set that is used to reconstruct a CT image expressing the scan field; and a CT image is then reconstructed based on the data set.
[Patent Document 1] Japanese Unexamined Patent Application Publication No. 2003-159244.
When a helical scan is performed using a multi-channel detector, a plurality of projection data items is acquired using X-rays that pass through the same pixel location in the same scan field while being transmitted along different paths with a scanner gantry set at the same view angle.
However, the conventional X-ray CT system does not utilize the plurality of projection data items but samples one projection data instead of projection data items that are acquired with the scanner gantry set at a certain view angle, and uses the sampled projection data to reconstruct an image.